Drilling-machine



(No Model?) GE C. TAFT. DRILLING MAGHINL O.

Platen'ted Nov. 13, |1883.

N. PETERS. Fnnlu-Lilhognphnr. washington: |J,C4

i UNITED STATES `PATENT OFFICE.

GEORGE c. Terr, or woEcEsrEn, MASSACHUSETTS.

D-RILLING- MACHINE,

SPECIFICATION forming part .of Letters Patent No. 288,510, datedNovember I3, 1883.

Application filed June 1, lEQ.

To a/ZZ whom it may concern: l

Be it known that I, GEORGE C. TAET, a citizen of theUnited States,residing at Worcester, in the county of Worcester and State of -Massachusetts, have invented a new and useful Improvement in SelfFeedingDrills, of which the following is a specification.

My invention relates to that class of selffeeding drills known ashorizontal,77 and has for its objects to aiiord facilities for adjustingthe feed,7 to provide `a quick return motion of the drill, and also tosecurely fasten the slidinglrest atthe bed.

The accompanying drawings represent a drill embodying my invention, inwhich Figure l shows a front elevation of the drill; Fig. 2, a sectionalview of the `main operating parts; Fig. 3, a detached view ofthe feedingdevice; Fig. 4, the sliding key or spline; Fig. 5, "a secf tional viewof the sliding rest.V

Similarletters refer tosimilar parts through out theseveral gures.

The standAsupports the rotating drillspin dle D, and from its baseextends the bed B, which carries the sliding rest C. The drill-l spindleD is inclosed by the screw E, which, working in the nut E, imparts afeeding inotion to the drill-spindle D. Rotary motion is given to thedrill-spindle D" by thev crank K; The eccentric L is afliXed to thedrill-spindle D and imparts a vibrating motion to the lever H, thepivotal bar 7L sliding into the base of the stand A as the drill-spindleand its connected mechanism advance. The upper end of the lever Hcarries the short lever I, pivoted at I', and having at its upper endthe actuating-pawl G, which, engaging with the teeth of theratchet-wheel F, gives an intermittent rotary motion to the attachedscrew E, and` accomplishes the feeding 7 of the drill-spindle.

Upon the upper end of the lever H are two lugs, d and f, projecting atright angles to the plane of its vibration, and at a sufficient distancefrom the secondary lever I to allow the lever I to vibrate between thetwo lugs at each vibration of the lever H, and consequently impart nomotion to the pawl G, the vibration of H being neutralized by thevibration of the lever I. In the lug f, I place the adjustingscrew g,which maybe advanced far enough (No model.)

'to completely check the vibration of the lever I on the pin I, when thetwo levers H and I will vibrate together and the pawl G be made to passover Several teeth of the ratchet-wheel, thus giving the maximuml amountof feeding motion to the drill-spindle desired, and by changing theposition of the screw any variation in the amount between these twolimits may be obtained.

In a suitable socket I place the Spring @,acting against the lug d, andthis spring should only be strong enough to hold 'the lever I -againstthe screw g when no resistance is oifered, the spring being easilycompressed at each forward motion of the lever` H without imparting anymotion to the lever I,pawl G, and ratchet-wheel F `until the lug dstrikes against the lever I. This is necessary, for if the spring isstiff enough to move the lever I and impart motion to theratchet-wheel,there by feeding the drill-spindle while the drill is atwork, the two levers H and I then become practically rigid, and movetogether, thereby preventing any adjustability of the feed by the screwg. Nor do I claim the use of asecondary lever attached to the vibratinglever and actuated by a spring instead of a driving-lug,

the spring being stiff enough to operate the ratchet against theordinary resistance in drilling, for` such a construction was shown anddescribed in Letters Patent granted to me March 24, 1857, No. 16,900, inwhich the force applied to the ratchet by the pawls was measured by theelasticity of the spring, which mightbe varied by means of an adjustablestop against the opposite side of the secondary lever. In my presentconstruction I use a Spring of only sufficient force to carry thesecondary lever against the adjusting-screw g, the lug d being used asthe driver and the secondary lever vibrating on I between the screw gand the driving-lug d at every vibration of the lever H, the screw gbeing employed not to increase the force of the spring, but to determinethe amplitude of the vibration, and the force applied to the ratchet ismeasured by that applied to the lever H at the eccentric L.

I accomplish the quick return motion of the drill in either of the twofollowing methods: In the hub of the ratchet-wheel F I place thebindingscrew P, which, through the brass or IOO copper plug P, pressesupon the drill-spindle D, so that the spindle and screw E will movetogether, when, the pawl G being thrown back from the ratchet-wheel andthe motion of the spindle D reversed by means of the crank K', the quickreturn of the drill-spin dle is effected. I also, in some cases, inplace of the above, make use of a key or spline, J, sliding in alongitudinal groove or keyway in the drill spindle D, and having theknob J', to afford an enlarged surface for the hand when 'being pushedin, and on the opposite end an enlarged portion, N, forming the shouldern. In the position shown in Fig. 2 this enlarged end N is inelosed inthe annular space M, the hub of the ratchet-'wheel revolving around it;butVv when the quick return of the drill is desired the key J is pushedin, the end Nentering a` rest C, so that the strain of the screw Q will.

come transversely to the base of the rest C, or in the section ofgreatest resistance, the side being properly strengthened for thepurpose of holdingthe screw. The countersunk indentations, by being onthe side instead of on the upper face of the bed, and also vby havingthe side slightly recessed, are protected from dirt and the falling ironchips resulting from the operation of drilling.

I am aware that a sliding rest has been be? fore used, sliding upon adovetail in the bed, and held by one or more binding-screws, whosestrain is thus brought transversely to the bed. Such a construction I donot claim.

I am aware that a vibrating lever has been used to operate the pawl in afeeding device; also, that a secondary pivoted lever has been beforeused, and such a construction was described in Letters Patent granted tome, and

dated March 24, A. D. 1857, No. 16,900, but for a different purpose, ofa different construction in some essential points, and having anentirely different mode of operation. Neither do I claim theconstruction and operation of the sliding spline or key J for thepurpose of effecting a quick return motion of the drillspindle referredto in the foregoingspecification, the same having been made the subjectof a separate application.

What I now claim as my invention, and desire to secure by LettersPatent, is-

l. The combination, in a drilling-machine, with the vibrating lever H,actuated by the eccentric L on the drill-spindle, the secondary lever I,pivoted to II at I/, the pawl G, and ratchet F, of the lugs d and f,placed at such distance apart as Will allow the lever I to vibratebetween them and impart no motion to the ratchet, the lug f carrying anadjustingscrew, g, having an endwise movement toand from the lever I,and the light spring e between the lever I and actuating-lug d, saidspring being only of sufiicient strength to carry the lever I againstthe screw g during the back-- ward motion of the lever H, allarrangedand operating as described, and for the purposeset forth.

2. IIn a drilling-machine, the combination, with the rotatingdrill-spindle D, of the hollow screw E, inclosing the drill-spindleD andworking in the fixed nut E', said hollow screw having abinding-screw,l?, by means of which the rotary motion of the drill-spindle may beimparted to the screw E, thereby -producing a rapid longitudinalmovement of the drill-spindle, as and for the purpose set forth.

3. In a drilling-machine,the combination, with the drill-spindle D, ofthe iiXed nut E and hollow screw E, inclosing the drill-spindle D, andhaving a binding-screw, I?, and a frietion block or plug, p, allarranged and operating as described, and for the purpose set forth.

Y GEO. C. TAFT.

Witnesses:

R. B. FowLER, A H. M. FoWLER.

